No Pro ?

I've been using the pro-edition with my iPhone for years. Now I'm moving to Android and of course I'ld like to continue with PocketCloud Pro BUT at least by now it's not possible to upgrade the free Play Store edition. As soon as I try to enter a second host the upgrade is suggested only to show 'not found' when triggered. Neither Google nor the forum search gave me reason so I'm asking: WHY ?

Maybe somebody can shed some light on this,

thanks in advance,

G. Fritz